Trigger connections - 7.1

Talend Data Management Platform Studio User Guide

Version
7.1
Language
English (United States)
Product
Talend Data Management Platform
Module
Talend Studio
Content
Design and Development

Trigger connections define the processing sequence, so no data is handled through these connections.

The connection in use will create a dependency between Jobs or subJobs which therefore will be triggered one after the other according to the trigger nature.

Trigger connections fall into two categories:

  • subJob triggers: On Subjob Ok, On Subjob Error and Run if,

  • component triggers: On Component Ok, On Component Error and Run if.

OnSubjobOK: This connection is used to trigger the next subJob on the condition that the main subJob completed without error. This connection is to be used only from the start component of a subJob.

These connections are used to orchestrate the subJobs forming the Job or to easily troubleshoot and handle unexpected errors.

OnSubjobError: This connection is used to trigger the next subJob in case the first (main) subJob do not complete correctly. This "on error" subJob helps flagging the bottleneck or handle the error if possible.

OnComponentOK and OnComponentError are component triggers. They can be used with any source component on the subJob.

OnComponentOK will only trigger the target component once the execution of the source component is complete without error. Its main use could be to trigger a notification subJob for example.

OnComponentError will trigger the subJob or component as soon as an error is encountered in the primary Job.

The main difference between OnSubjobOK and OnComponentOK lies in the execution order of the linked subJob.

  • With OnSubjobOK, the linked subJob starts only when the previous subJob completely finishes.
  • With OnComponentOK, the linked subJob starts when the previous component finishes.

The execution order of the subJobs linked by OnComponentOK is within the execution cycle of the previous subJob.

Run if triggers a subJob or component in case the condition defined is met. For further information about Run if, see Run if connection settings.

For how to set a trigger condition, see  Trigger connection settings.

Note: It is possible to add checkpoints to certain trigger connections in order to be able to recover the execution of a Job from the last checkpoint previous to the error. For more information, see Setting checkpoints on trigger connections.